Computers and other information technology systems typically contain semiconductor devices such as memory. The semiconductor devices are controlled by a controller, which may form part of the central processing unit (CPU) of a computer or may be separate therefrom. The controller has an interface for communicating information to and from the semiconductor devices. It is known that errors can sometimes occur in the communicated information for various reasons, and many known systems lack a capability of correcting errors, or at least lack a satisfactory capability of correcting many of the errors.